Numerous methods have been disclosed for the preparation of tetrachloropropenes, including 1,1,3,3-tetrachloroprop-1-ene (1230za). These methods vary widely in both starting materials, reaction conditions, and selectivity.
U.S. Patent Application Publication Nos. 2011/0083955 and 2011/0087055 disclose methods for preparation of 1230za through the reaction of methylene chloride and trichloroethylene. These methods produce 1230za with up to 94% selectivity.
U.S. Patent Application Publication No. 2013/0211155 discloses a method for preparing 1230za by a dechlorination reaction with Zn metal of CCl3CHClCHCl2 (230 da) in a CH3OH solvent with formation of 1230za in 70% yield.
U.S. Pat. No. 5,689,020 discloses a high temperature chlorination process in which mixtures of propene and/or chlorinated propenes diluted in CCl4 or N2 are chlorinated with Cl2 to provide mixtures of 1230za and 1,3,3,3-tetrachloropropene (1230zd).
U.S. Patent Application Publication Nos. 2012/0190902 and 2011/0196178 disclose methods for stabilizing tetrachloropropenes using antioxidants.
U.S. Pat. No. 7,094,936 discloses a method for producing 1230za by reaction of CCl4 with vinyl chloride. Liquid phase dechlorination of 1,1,1,3,3-pentachloropropane (240fa) to form 1230za is also disclosed.
U.S. Pat. No. 3,497,565 discloses a process for production of chloropropenes by chlorination of chloropropenylsulfides with Cl2.
French Patent No. FR 1.496.124 and British Patent No. GB 1,181,873 disclose a process for chlorination of alkenyl thioesters to produce a mixture of 1230za and 1230zd. A method for converting 1230zd to 1230za is also disclosed.
U.S. Pat. No. 8,304,589 discloses a method for production of 240fa from CCl4 and vinyl chloride. A process for thermolysis of 240fa to 1230za at a temperature of 500° C. is also disclosed.
There is a need for a method of producing tetrachloropropenes with high selectivity and purity that is scalable up for commercial manufacturing.